Question

If the angle of incidence and angle of emergence of a light ray falling on a glass slab are $i$ and $e$ respectively, prove that , $i=e$

Answer 1

If the angle of incidence and angle of emergence of a light ray falling on a glass slab are given then by applying Snell’s law we can get,

$\frac{\sin i}{\sin r}=\frac{n_2}{n_1}$

$\frac{\sin r}{\sin e}=\frac{n_1}{n_2}$

On multiplying the above two equation we get

$\frac{\sin i}{\sin e}=1$

$\sin i=\sin e$

Hence the angle of incidence is equal to the angle of emergence